Are pure substances homogeneous or heterogeneous

Which has the highest lattice energy BaO or SrO

Imagine that a chemist is trying to establish whether a piece of rock is from a meteorite that fell from outer space. the rock contains more copper-65 atoms than copper - 63 atoms. what can you conclude

Why does the ozone layer important to life on earth?

Which statement about a chemical reaction is true? It occurs only at low temperatures. It occurs only at high temperatures. It occurs whenever a physical change takes place It occurs whenever a chemical change takes place.

Which of the following is NOT one of the three processes that were most intense during the first few hundred thousand years of the Earth's history?

Carbon-14 has a half-life of 5730 years. In a plant fossil, you find that the 14C has decayed to 1/4.00 of the original amount. How long ago was this plant alive?

Balance this equation---> Fe (s) + O2 (g) - - - >FeO (s) (s) = solid (g) = gas

During an endothermic phase change, what happens to the potential energy and the kinetic energy?

What is the difference between pure substance, element, and compund

Butane gas is used as the fuel in disposable lighters. It burn in oxygen to form carbon dioxide gas and water vapor. What mass of carbon dioxide is produced when 53.3 g of butane is burned in 103.9 g of oxygen